Chemotherapeutic agents conjugated to p97 and their methods of use in treating neurological tumours

Abstract

The present invention provides pharmaceutical compositions of chemotherapeutic agents that demonstrate therapeutic efficacy against brain tumours and other neoplasia localized in or around the brain. In certain aspects, the pharmaceutical compositions comprise a chemotherapeutic agent conjugated to p97; and a pharmaceutically acceptable carrier therefor. Preferred chemotherapeutic agents include, but are not limited to, adriamycin, cisplatin, and paclitaxel.

What is claimed is:  
     
         1 . A pharmaceutical composition, said pharmaceutical composition comprising: 
 a chemotherapeutic agent conjugated to p97; and    a pharmaceutically acceptable carrier therefor.    
     
     
         2 . The composition of  claim 1 , wherein the chemotherapeutic agent is selected from the group consisting of adriamycin, cisplatin, paclitaxel, camptothecin, 5-fluorouracil, and analogs thereof.  
     
     
         3 . The composition of  claim 2 , comprising p97-adriamycin.  
     
     
         4 . The composition of  claim 2 , wherein said chemotherapeutic agent comprises at least two different chemotherapeutic agents.  
     
     
         5 . The composition of  claim 2 , wherein said chemotherapeutic agent comprises a cardiotoxic agent.  
     
     
         6 . The composition of  claim 2 , wherein conjugation of said chemotherapeutic agent to p97 involves a linker comprising an organic moiety, selected from the group consisting of an alkyl, acryl or amino acid backbone.  
     
     
         7 . The composition of  claim 6 , wherein said organic moiety comprises an amide, ether, ester, hydrazone, sulphide or disulphide linkage or any combination thereof.  
     
     
         8 . The composition of  claim 6 , wherein said conjugation is stable at physiological pH.  
     
     
         9 . The composition of  claim 8 , wherein said conjugation is unstable at intracellular pH.  
     
     
         10 . The composition of  claim 2 , wherein said conjugation is by a sulfhydryl linker.  
     
     
         11 . The composition of  claim 2 , wherein the molar ratio of said chemotherapeutic agent to p97 is at least 2:1.  
     
     
         12 . The composition of  claim 2 , wherein the molar ratio of said chemotherapeutic agent to p97 is at least 7:1.  
     
     
         13 . The composition of  claim 2 , wherein the molar ratio of chemotherapeutic agent to p97 is at least 10:1.  
     
     
         14 . The composition of  claim 10 ,  11  or  12 , wherein said chemotherapeutic agent is adriamycin.  
     
     
         15 . The composition of  claim 1 , where the chemotherapeutic, agent is selected from the group consisting of alkylating agents, antimetabolites, natural products (such as vinca alkaloids, epidophyllotoxins, antibiotics, enzymes and biological response modifiers), topoisomerase inhibitors, microtubule inhibitors, spindle poisons, hormones and antagonists, and miscellaneous agents such as platinum coordination complexes, anthracendiones, substituted ureas, and analogs thereof.  
     
     
         16 . A pharmaceutical compositional said pharmaceutical composition comprising: 
 a chemotherapeutic agent conjugated to p97 comprising a dosage unit of from about 0.02 to about 2000 mg/kg of p97, substantially all of which p97 is conjugated to said chemotherapeutic agent; and    a pharmaceutically acceptable carrier therefor.    
     
     
         17 . The composition of  claim 16 , wherein said chemotherapeutic agent is selected from the group consisting of adriamycin, cisplatin, paclitaxel, or an analog thereof.  
     
     
         18 . The composition of  claim 16 , wherein said dosage unit comprises from about 0.1 to about 100 mg/kg of said chemotherapeutic agent.  
     
     
         19 . The composition of  claim 16 , wherein said dosage unit comprises from about 0.1 to about 10 mg/kg of p97.  
     
     
         20 . A method for increasing delivery of a chemotherapeutic agent to a neoplasia localized in or around the brain, said method comprising administering a p97-chemotherapeutic agent to an animal having a neoplasia in or around the brain, wherein the amount of chemotherapeutic agent delivered as part of the p97-chemotherapeutic agent to said neoplasia is increased relative to delivery of the chemotherapeutic agent when said chemotherapeutic agent is not conjugated to p97 and administered at an equivalent dose.  
     
     
         21 . A method according to  claim 20 , said method comprising: 
 a) conjugating a chemotherapeutic agent to p97 to generate a p97-chemotherapeutic agent; and    b) administering said p97-chemotherapeutic agent to an animal having a neoplasia in or around the brain, wherein the amount of chemotherapeutic agent delivered as part of the p97-chemotherapeutic agent to said neoplasia is increased relative to delivery of the chemotherapeutic agent when said chemotherapeutic agent is not conjugated to p97 and administered at an equivalent dose.    
     
     
         22 . A method for targeting a chemotherapeutic agent to a neoplasia localized in or around the brain, said method comprising administering a p97-chemotherapeutic agent to an animal having a neoplasia localized in or around the brain, wherein said patient experiences increased delivery of said chemotherapeutic agent to said neoplasia compared to when the chemotherapeutic agent is not conjugated to p97 and is administered at an equivalent dose.  
     
     
         23 . A method according to  claim 22 , said method comprising: 
 a) conjugating a chemotherapeutic agent to p97 to generate a p97-chemotherapeutic agent, and    b) administering the p97-chemotherapeutic agent to an animal having a neoplasia localized in or around the brain, wherein said patient experiences increased delivery of said chemotherapeutic agent to said neoplasia compared to when the chemotherapeutic agent is not conjugated to p97 and is administered at an equivalent dose.    
     
     
         24 . A method of treating a neoplasia localized in or around the brain comprising administering to a subject in need thereof a pharmaceutically effective amount of a p97-chemotherapeutic agent.  
     
     
         25 . The method of  claim 24 , wherein said p97-chemotherapeutic agent is p97-adriamycin.  
     
     
         26 . The method of  claim 25 , wherein the molar ratio of adriamycin to p97 is at least 2:1.  
     
     
         27 . The method of  claim 25 , wherein the molar ratio of adriamycin to p97 is at least7:1.  
     
     
         28 . The method of  claim 25 , wherein the molar ratio of adriamycin to p97 is at least 10:1.  
     
     
         29 . A p97-chemotherapeutic agent conjugate selected from the group consisting of:  
       
         
           
           
               
               
           
         
       
     
     
         30 . A modified adriamycin molecule selected from the group consisting of:  
       
         
           
           
               
               
           
         
       
     
     
         31 . A method of preparing a p97-adriamycin conjugate comprising the steps of: 
 dissolving adriamycin in an inert solvent, and adding an organic base, preferably triethylamine;    adding a solution of SMCC in an inert solvent,    adding mercapto acetic acid;    adding a coupling reagent;    adding the solution of adriamycin, base, SMCC, mercaptoacetic acid and coupling reagent slowly to a solution of p97 and reacting under conditions to provide adriamycin-p97 conjugates; and    purifying the adriamycin-p97 conjugates.    
     
     
         32 . The method according to  claim 31 , wherein the inert solvent is DMF.  
     
     
         33 . The method according to  claim 31 , wherein the organic base is a trialkylamine.  
     
     
         34 . The method according to  claim 31 , wherein the coupling reagent is O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU).  
     
     
         35 . A method of detecting or diagnosing a cancer of the brain comprising administering an effective amount of a composition comprising a radioimaging agent conjugated to p97 to an animal in need thereof.  
     
     
         36 . A method according to  claim 35  wherein the radioimaging agent is technetium-99M.